SOP for Wire Nail Manufacturing
1. Preparation (Before Start-Up)
| Step | Action | Key Checkpoint |
| 1.1 Raw Material | Select and ensure the steel wire coil is of the correct gauge (diameter) and material specification (e.g., cold drawn, bright wire) for the required nail size. | Raw material spec sheet matches production order. |
| 1.2 Machine Check | Lubricate all designated points (e.g., transmission parts, cutting dies) as per the machine's maintenance schedule (e.g., 3 times per shift). | Adequate oil/lubricant visible at all points. |
| 1.3 Tooling & Dies | Install the correct size gripping dies and nail knife/cutter set according to the desired nail length and head size. Ensure the nail knife is sharp. | Dies and cutter are correct size, secure, and sharp. |
| 1.4 Safety Check | Ensure all safety guards are in place. Manually rotate the flywheel for one full revolution to confirm no obstacles or loose fasteners exist before powering on. | No obstructions; all fasteners tight; safety signs posted. |
2. Operation Procedure (Nail Production)
| Step | Action | Key Checkpoint |
| 2.1 Power On | Start the machine and allow it to reach its normal operating speed. | Machine running smoothly without abnormal noise. |
| 2.2 Wire Feeding | Feed the wire from the coil through the straightening rollers and into the machine's feeding mechanism and gripping dies. Only turn on the wire feed after the machine is running normally. | Wire feeds smoothly; no snagging or excessive tension. |
| 2.3 Forming & Cutting | The machine performs the continuous cycle: 1) Gripping, 2) Heading (forming the nail head), 3) Pointing/Cutting (shearing the nail point and separating it from the wire). | Continuous, rapid nail ejection. |
| 2.4 In-Process Check | Continuously monitor the machine for: * Temperature rise in friction parts. * Abnormal noise or vibration. * Consistent nail quality (see Section 3). | Stop machine immediately if abnormal conditions occur. |
3. Quality Control (QC) & Inspection
| Step | Action | Criteria/Tolerance |
| 3.1 Visual Check | Frequently inspect a sample of produced nails (e.g., every 15-30 minutes). | No burrs on the head or shank. Head is fully formed and centered. Nail point is sharp and correct shape (e.g., diamond). |
| 3.2 Dimensional Check | Use a caliper/gauge to measure key dimensions on samples. | Length must be within specified tolerance ($\pm$ tolerance). Head diameter must meet spec. Wire gauge (shank diameter) must be correct. |
| 3.3 Functionality | Check the nail for straightness. | Nail must be straight; no bends or kinks. |
| 3.4 Adjustment | If quality issues are detected, stop the machine immediately and adjust the tooling (e.g., nail knife position, die pressure) before restarting. Never adjust the workpiece while the machine is running. | Quality returns to spec before resuming full production. |
4. Post-Production & Finishing
| Step | Action | Note/Equipment |
| 4.1 Polishing (Optional) | Transfer finished nails to a polishing drum with tumbling media (e.g., sawdust, polishing powder) to remove oil, burrs, and clean the surface. | Results in a "bright" finish and better aesthetic/rust resistance. |
| 4.2 Plating (Optional) | If required (e.g., galvanized nails), transfer to the plating/coating line. | Provides corrosion resistance. |
| 4.3 Packaging | Count, weigh, and package the finished, inspected nails into boxes, bags, or coils according to the product specifications. | Ensure correct count/weight and proper sealing/labeling. |
5. Shut Down & Maintenance
| Step | Action | Key Consideration |
| 5.1 Stop Feed | Stop the incoming wire feed first. | Allow remaining wire to cycle out and form the last nails. |
| 5.2 Power Off | Turn off the main machine power. Strictly forbidden to brake the flywheel by hand. | Wait for the machine to stop naturally. |
| 5.3 Cleaning | Clean the machine, dies, and work area, removing all wire scraps and debris. | A clean machine is essential for the next production run. |
| 5.4 Repairs | If repairs are needed, disconnect the power supply and hang a clear "Do Not Operate/Maintenance In Progress" sign. | Follow Lockout/Tagout procedures. |
